This invention relates to means for restraining movement of cargo while it is being transported on a movable platform. In particular, the invention relates to a restraining device with a pressure surface at one end, the device comprising means to lock it in any one of a plurality of locations uniformly spaced apart in one direction, the device including means to move the pressure surface in smaller steps from one of the locations to the next and further means to move the pressure surface incrementally between successive ones of the steps.
The need for providing some means for preventing undesired movement of cargo while it is stored or is being transported by a moving vehicle has long been recognized. One way to limit such movement is to provide a series of surfaces, such as the faces of the teeth of a rack or rachet or the side walls of a series of holes evenly spaced apart in one direction, the surfaces being substantially perpendicular to that direction. A blocking device provided with projecting means can be positioned to allow the projecting means to make contact with one or more of the surfaces to hold the blocking device in a fixed location chosen to prevent movement of the cargo in at least the one direction. In U.S. Pat. Nos. 1,949,218 to Owens and 2,764,105 to Stiegel, the surfaces are gear or ratchet teeth engaged by a pawl or the like. The surfaces can also be sides of holes on an elongated member as shown in U.S. Pat. Nos. 4,200,046 to Koliba and Napel and 4,217,831 to Koliba, Oakes, Jr., and Napel. In both of the latter patents, the surfaces defining the side walls of the holes in the elongated member are engaged by studs that extend from a blocking device and, once in one of the holes, have to be twisted to be locked in place.
In all of the foregoing patents the surface of the blocking device that engages the cargo can only be positioned at certain fixed points spaced apart from each other by the distance between successive ones of the surfaces engaged by the projection means, that is, by the distance between successive gear or rachet teeth in the devices of Owens and Stiegel and successive holes in the cases of the two Koliba, et al. devices.
It is frequently desirable to hold the cargo in a certain position that would be between the fixed positions of the aforesaid patents. In FIG. 8 of U.S. Pat. No. 4,027,812, Parks shows a cargo restraining assembly that provides adjustable blocking means. However, the blocking means are opposing wedges that engage studs mounted in the holes at specific locations in the false floor of a cargo vehicle. The wedges are entirely separate from the studs, not lockingly engaged with them, and not necessarily available when needed.
Bott in U.S. Pat. No. 4,717,298 and Joice-Cavanagh in U.S. Pat. No. 4,396,325 show means for blocking the position of cargo at any location along a longitudinal direction, but the blocking is effected by frictional means, which could be forced loose by the continuing vibrational movement of the cargo vehicle.